[e] (0) Clarify IDs are not restricted.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=21282
Affected topics: HTML

git-svn-id: http://svn.whatwg.org/webapps@7872 340c8d12-0b0e-0410-8428-c7bf67bfef74
[giow] (2) Allow data: URLs to be given download='' attribute names.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=21505
Affected topics: HTML

git-svn-id: http://svn.whatwg.org/webapps@7873 340c8d12-0b0e-0410-8428-c7bf67bfef74